Gas Chromatography - Mass Spectrometry

Chromatography is a family of analytical chemistry procedures for the division of mixtures. Chromatography consists of passing the specimen (sample), a mixture that includes the analyte, in what is termed the "mobile phase", frequently in a solvent stream, through what is known as the "stationary phase." The stationary phase slows down the transit of the components of the specimen. As component parts travel through the system at various speeds the parts become separated in terms of time, like runners in a long-distance race. Every component has a unique (or characteristic) time of travel through the system, often referred to as the "retention time." Chromatographic separation is attained when the retention time of the analyte is different from other sample components.

Gas Chromatography

Gas Chromatography utilizes a carrier gas, such as helium or nitrogen and a pressurized gas cylinder to carry the sample through the column. The two most common detectors used are flame ionization and thermal conductivity detectors. Polyhedron handles solvents, monomers and additives and utilizes Head space (analysis) Gas Chromatography for residual monomers or solvents.

GC Mass Spectrometry

Gas Chromatography - Mass Spectrometry (GC-MS) is a type of chromatography that combines the features of gas chromatography and mass spectrometry to distinguish and identify various components in a test sample. It is comprised of two systems - the mass spectrometer and the gas chromatograph. The two combined components, when used together, deliver a substantially finer degree of sample (substance) identification than using each component separately. Another result of combining the two systems (and processes) is that it is highly improbable that two different materials will behave in the same manner in both a mass spectrometer and a gas chromagraph. Polyhedron Laboratories performs GC-MS analysis using the AMDIS and the NIST02 mass spectra database. In addition, Polyhedron performs Pyrolysis GC-MS, Head Space GC-MS, target compound analysis, and semi-quantitative analysis by forward library searching. SIM GC-MS is available for target compound analysis.

Thin Layer Chromatography

In Thin Layer Chromatography (TLC), the stationary phase is comprised of a thin layer of adsorbent such as cellulose, alumina, or silica gel on a flat carrier, typically a plastic sheet, thick aluminum foil, or a glass plate. Some of the advantages of Thin Layer Chromatography include a choice of different adsorbents, better separations, and faster runs. Thin Layer Chromatography is frequently used for the qualitative analysis of reaction components and monitoring chemical reactions due to its speed and simplicity. Polyhedron Laboratories offers Adsorption and reversed phase Thin Layer Chromatography, as well as Quantitative (Iotroscan).